| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for efficiently removing unwanted signals without increasing the circuit size of a receiver. SOLUTION: A spurious detection circuit 94 detects a frequency f2 of a spurious signal from the reception signal of a frequency region outputted from an FFT computing unit 10, and calculates a phase rotation amount (p) in a time domain from the difference between a stop frequency f1 of a notch filter 92 and a spurious frequency f2 to set it to a rotator 91 and a derotator 93. The rotator 91 rotates the phase of the reception signal based on the phase rotation amount (p). The notch filter 92 attenuates the spurious signal having a frequency adjusted to f1. The derotator 93 reversely rotates the phase of the reception signal based on the phase rotation amount (p). The FFT computing unit 10 demodulates the reception signal from which the spurious signal has been removed. COPYRIGHT: (C)2009,JPO&INPIT
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